and love.There's an app called photone free for Android phones, install it and calibrate it against your light ppfd chart, it's pretty accurate and gets us in the ball park.
Light intensity rules everything else we just can't expect same hps yield giving lower light intensity with LEDs that's a fact.
The most important thing is light intensity, than it's Leaf surface temperature (air temps and RH too), co2, water content/drybacks, rootzone health, wind, nutrients.
I'm old you speak of things I know nothing about app? android I have a phone on the wall, I think its a Bell.